He is one of our best-loved painters, but now it is claimed some of John Constable’s best-known works may be – to put it perhaps a little unkindly – cut-and-paste jobs.

Experts have noticed similarities between parts of some of John Constable’s works (Picture: Bonhams)

Under pressure to hit deadlines, the artist would get right-hand man Johnny Dunthorne to trace the rough outlines of his small paintings, research suggests.

Later on, Dunthorne would transpose the crudely copied sections on to larger canvases intended for major works.

The ‘one-I-made-earlier’ technique came to light when experts spotted close links between a 25cm picture up for sale at auction and two renowned paintings of Branch Hill Pond, on Hampstead Heath in London.

Showing men struggling with a horse and cart, it has cuts in it made while the paint was still wet – thought to be the marks left by Dunthorne’s tracing.

A similar scene crops up in the bottom-right sections of the Branch Hill Pond pictures, suggesting Dunthorne pencilled it in to both.

At the time his paintings of the pond were commissioned, Constable was at the height of his fame and had a flood of commissions to cope with.

Dave Dallas, of London auctioneer Bonhams, said: ‘The incised marks on the study confirm what was long suspected – Dunthorne traced key elements by Constable for use in major works.

‘The study reputedly comes from the artist’s studio and was passed down to one of his granddaughters.’.